Shock absorber



May 27, 1930.

w. A. cHRYsT v S HOCK ABSORBER Filed Nov. 18, 1927 Patented May 2.7,1930 UNITED STATES WILLIAM A. cHRYsT, oF DAYTON, omo,

WARE

PATENT OFFICE ASSIGNOR, BY MESNE ASSIGNMENTS,v T' l DELCG PRODUCTSCORPORATION, 0F DAYTON, OHIO-J A CORPORATION 0F DELA- v snoek ABsoBBEB.f

Application led November 18, 1927. Serial No. 234,113.

This invention relates to improvements in shock absorbers for checkingthe'movement of two relatively movable members, for examplethe frame andaxle of an automotive vehicle. l

It is amongthe objects of the present invention to provide a shockabsorber of simple and compact construction Jfor resisting theapproaching movement of the frame and 30 axle as well as retarding themovement of separation of these members.

Further objects and advantages of the resent invention will be apparentfrom the ollowing -description,reference being had to the accompanyingdrawings, wherein a preferred' embodiment of one form of the` presentinvention is clearly shown.

, In the drawings:

Fig. 1 illustrates the front portion of the 30 lframe of an automobilesupported by a spring upon the usual -axle with the shock absorber,embodyingv the present invention, applied thereto. L

Fig. 2 is a vertical sectional 4view of the shock absorber, certainportions therein being shown in elevationv for the sake of clearneSS. v

Referring to the drawings, the numeral 2O designates the main girder orside frame oi' the vehicle, having a' downwardly bent' end to which oneend of a spring 21 is pivotally secured. The other end of said spring 21is attached to the frame by a link 22 in is connected with the lever 26by a rod 28,-'

the usual manner. Intermediate its ends, spring 21 rests upon the axle23.

The shock absorber is secured to the side frame of the lvehicle andcomprises a casing 24 having journalled therein a rockshaft 25, to whichis secured a relatively long arm or lever 26. A bracket 27 secured to.theaxle 23 the ends of which are swivelly secured to the lever 26 andbracket 27 respectively.

The casing 24 preferably is attached directly to the frame 20, lugsv(not shown) beingformed on the casing for attaching purposes.

A cover 29, provided with a gasket 30, is held in sealing engagementwith the casing vby screws 31. The casingv 24 provides a iiuid chamber32 divided into two compartment-s by a partition wall 35, saidcompartments presenting adjacent cylinders 33 and 34, the cylinder 33being longer than the cylinder 34.

Pistons 36 and 37 are reciprocally mounted in the cylinders 33 and 34respectively. The

head of the piston 36 has an opening 3.6a v,

bridged by a lug 38 to which is connectedone end of link 39. Thefotherend of said link 39 is secured tothe end of a rocker arm 41, formed onla hub' portion 40 which is secured to the rock shaft bv a set screw 40aso as' to rotate therewith.

The piston 36 is provided with a check valve comprising., a valve seat`rnember 42 havingaiiange which is held engagement with the innersurface oi the piston head by a spring 43, which is interposed betweensaid valve seat member` 42 and the bottom end ofcylinder 33. The valveseat member 42 has a plurality ofapertures 44 arranged in a circular rowabout a central portion to which issecured a pin 45. A' vaiveplatemember 46 is slidably carried by said pin 45 and -held in normalengagementwith the valve seat member by a spring'v47 surrounding. pin45, one end of said spring 47 engaging the valve plate member 46, theother end resting upon an v1 abutment member 48 re' tained upon the pin45 by aC-washer 49. They skirt-of the piston 36 has two apertures 5,0Vin superposed relation, said apertures being adapted, when moved inalignment with. the

through-passage 51 in the partition 35, to

complete communication between the cylin- 1 ders 33 and 34.

that the plug 55 is in coaxial alignment withv p a lvalve member 53adapted to be held in yielding engagement with a valve seat 53a formedin the partition 35 about the through passage 51. y Spring 59 surroundsthe valve stem 54 and is interposed between the end of the plug y 55 andthej valve member 53. A tubular extension 52 provided with apertures 57,is slidably supported in the through-passage 51. lAs shown lin Fig. 2,the valvestem is hollow throughout the major portion of its length,however, a small orifice 58 is provided at the end extending into therecess 56 through which Huid from the valve stem 54 may fiow into therecess 56 and then from said recess into the cylinder 34 due lto thedifference of diameters betweenl the. recess 56 and valve stem 54. d

The partition has a ledge 61 formed thereon, said ledge cooperating withthe boss to provide a seat ,within the cylinder 34, for the abutmentplate'60.` One end of a spring 62 rests u on the abutment plate 60, theother end o said spring supports the piston 37 In the skirt of thepiston 37 and vi ed an aperture 63 which' normallyprovidescommuni-cation between the Huid chamber 32 and the interior ofthe cylinder v34 beneath the piston 37. A portion 63a of a wall of thecasing is positioned adjacent the aperture l63 so as to gradually coversaid aperture and provide a gradually increasing restriction to the flowof `fluid. through said aperture as the piston 37 is moved downwardly. f

A transverse slot or groove 64 formed in -the outer surface of the headof piston 37 recomparatively smooth road, the springs 21 will functionto absorb shocks which vresult from slight irregularities in the roadbed.;

However, when the road wheels of the vehicle strike a comparativelylarger obstruction, the axle 23 will be forced upwardl toward the frameof the vehicle which exes the springs 21 in the same direction.` Thesprings, after reaching their limit of flexure, will rebound, however,

having been started in an upwardly direction by the spring pressure,will tend t-o continue in the lupward direction until gravity andreturning spring action cause a sudden reversal of body movement. Such asudden reversal 4 causesjarring shocks to the occupant of the vehicle.In the resent device when a spring f 21 is moved a su stantial distancetoward the' vehicle frame by reason of the road wheels striking asubstantial obstruction, the rod slightly below the piston head, thereisproy the frame and body,

28 will move the lever 26 in a direction to rotate the-rock shaft 25counter-clockwise as v viewed in the drawings. Such movement of the rockshaft 25 will cause the cam 65 to move the piston 37 downwardly into itscylinder 34 against the action of the spring 62 andthe rocker arm -41will, through the medium of links 39, move piston 36 upwardly in itscylinder 33. The upward movement of piston 36 causes the fluid in thefluid chamber 32 to move the valve plate 46 away from its seat member 42against the action of. spring 47. A free lio-w of fluid from the iiuidchamber 32 to the interior of the cylinder 33 beneath the piston 36 visnow established through passages 44. The downward movement of piston 37compresses the fluid and spring beneath it, the degree of such.compression being dependent upon the extent and suddeness of thedownward movement of the piston 37. If the downward .movement of thepiston is slight due to com aratively slight axle movement toward therame, the

compression of the fiuid. beneath the piston will be of comparativelysmall degree inasmuch as the partially closed aperture 63 will providefor a substantial iow of fluid from the cylinder 34 to the fluid chamber32. How- ,i

ever if the axle 23 is'moved suddenly tnd for a substantial distancetoward the frame 20,

the piston 37 will be moved into its cylinderl 34, thereby substantiallyclosing the aperture 63. v The compression 'of the fluid under thesecircumstances will resist the piston movement downwardly and cause thedevice to function as a bumper. The fiuid pressure resistance to thedownward movement ofthe piston 37 is, however, slightly relieved by theleakage of -fiuid from cylinder 34 to cylinder 33 through the recess 56,orifice 58, valve stem 54 and through-passage 51. lFrom this it may beseen that the present device provides a resistance to the fiexing of thesprings 21 which resistance increases more rapidly f as the springsapproach their limit of flexure. As has been mentioned heretofore, the

lll

frame 20, with the bodyof the vehicle supy ported thereon, will tend tomove upwardly after the spring 21 commences to movetoward its normalunflcxed position. `The separation of the frame and axle causes the rod28 to movefthe lever in a direction to rotate the rock shaft 25clockwise, as viewed in the drawings, thereby causing the rocker arm 41and its link 39 to move'the piston 36 downwardly. The fluid underpressure beneath the piston 36 closes the valve 46 after which sage 51,valve stem 54, orifice 58 into recess 56 and then between the valve stem.54 and the wall of the recess 56 into the cylinder 34. A

s bstantial resistance to the downward moveent ofthe piston 36'obtainsdue to therestriction at the orifice 58. When a predetermined high fluidpressure is attained withthe fluid will flow through vthethrough-pasthefthrough-passavel and the cylinder 34,

thus;providing ahy-pass. .around the orifice 58 for relievin theexcessive fluid pressure m' within' the cy inder 33.v A predeterminedpressure 1s necessary to open'the valve 53 against the resistance ofspring. 59, however, after the valve has beenopened, the pressure can besubstantially diminished before theI valve 53 will'again close,v due tothe increased areav of the valve subjected to the fluid pressure whenthe valve .is open. Theuidpressure resisting the moveme ofthe piston 36`downwardly into its cylinder will retard the movementof separation ofthe axle 23 and frame 20 in accordance with the deflection of spring 21,said retardation tending to dissi- 'pate the rebound shock whichiresultsfrom sudden separation'of said axle and frame.

The head of the piston 37 is provided with a passage 7 0. which isnormally closedby a spherical relief valve 71 yieldingly maintain- `edon its seat 72 by a spring/73 which is held in position by pin 74extending into the passage 70. When the acceleration of the relativeapproaching movement of the frame and axle exceeds a certain amount,thereby causing an` abnormal pressure to exist below the head of thepiston 37,l the relief valve 71 will open to relieve this pressure andthereby prevent undue` strains upon the shock ab`l sorber. v While theform of embodiment of the present invention as herein disclosed,constitutes.

a preferred form, it is to be understood that other forms might beadopted, all coming within the'scope of the claims which follow.

What is claimed is as follows:

" 1. A shock absorber for cushioning the mentioned means' whereby themovement of two relatively movable members, comprising in combination, acasing adapted to be secured to one of said members, presenting a'iiuidchamber and cylinders; pistons reciprocal in said cylinders;

means connected to the other relatively movable member and .adapted tooperateeach of said pistons in one direction; .an aperture through theskirt of the one piston, so positioned relatively to a wall of thecasingas to be gradually covered by said wall in'response to the movement ofsaid piston b the aforeow of iuid through said aperture is gradually,increasingly restricted; and a valve in the other pis- .ton forestablishing a freelow of uid therethrough during said movement of thevfirst mentioned piston.

2. A shock absorber for cushioning the movement of two relativelymovable members, comprising in combination, a casing adapted to besecured one of said members, presenting a luid chamber and cylinders;

pistons reciprocal in said cylinders; means f i connected to the otherrelatively movable member and ada ted to operate each of said pistons inone direction; and a valve interposed between the cylinders and ada tedto provide a Avariable resistance to the ow of fluid from the onecylinder to the other when f 75 3. A shock absorber'for cushioning 'themovement of two relatively movable members, comprising in combination, acasing adapted to be secured to one of said members, presenting a iuidchamber .and cylinders; pistons reciprocal in said cylinders;

means connected to the other relatively movable member and adapted tooperate each of said pistons in onedirection.; Huid controlling meansfor establishing a gradually,increasing restricted flow of fluid throughthe one piston in response to the movement of said piston by itsoperating means; and a valve interposed between the cylinders andadapted to prqyide arestricted constant flow relief passage for theiowmf iiuid 4from the-cylinder of the said one iston to the othercylinder, said valve romding al variable resistance to the flow of uidfrom the said'othercylinder to the first lmentioned cylinder in responseto the downward movement vof vthe piston in said other cylinder.

4. A shock absorber for cushioning vthe the lother relatively movablemember, said rock-shaft having arms within the ,casing which engage thepiston to operate. each vof V.them in one direction; means forestablishing a free flow of fluid fromthe Huid cham.-

ber through the one-piston into its respective cylinder in response tothe movement of the, two relatively movable members toward each other;and an aperture through the skirt of the other piston directly beneathits head portion for establishin a graduall increasing restricted flowof fluid through t e said other `piston in. response to vsaid movementof the two relatively movable members.

v 5.l A shock absorber fgr cushioning the movementof two relativelymovable members, comprising, a casing adapted to' be secured to one ofsaid members, presenting a uid chamber and) cylinder; pistons reciprocalin said cylinders; means operatively connected to the other of saidrelatively movable members and engaging the pistons alternately tooperate them in the same direction in response to movement between therelatively movable members; means in the one piston to 5 establish afree flow of luid from the fluid chamber through said piston into thecylinder thereof in response to approaching movement of the saidmembers; and an aperture in the skirt of the other piston, directlybeneath the piston head portion for establishing a gradually increasingrestricted flow from the inside of said piston through the aperture toythe fluid chamberl in response tothe said tively connected tol/theother relatively movable member, said rock shaft having arms within thecasing which engage the istons for operating one or the other pistonlnto its cylinder in response to the movement of said members toward oraway from each other;

. an opening through the skirt `of the one piston, gradually covered bythev movement of the said one iston for graduallyA restricting the flowof uid from the cylinder beneath said piston throu l1 the opening in itsskirt to the fluid chamer upon movement of the relatively movablemembers toward each other; means in the other piston for establishing afree flow of fluid from the fluid chamber into the cylinder beneath saidpiston during' the said movement ofsaid members; and means comprising avalve interposed between the two cylinders and having one constantlyopen passage for delivering fluid from the one cylinder to the other ata restricted flow when either piston is moved into its cylinder.

7. A shock absorber for cushioning the movement of two relativelymovable members comprisin a casing adapted to be secured to one o saidmembers presenting a fluid chamber and two cylinders; a pistonreciprocal in each'of said cylinders; a rock shaft journalledy in said.casing and operatively connected to the other relatively movablemember, said rock shaft havin-g` arms within the casing which engage thepiston for operating one or the other piston into its cylinder inresponse to the movement of said members toward or away from each other;means controlled by the movement of the one piston-for establishing agradually restricted flow of fluid fromthe cylinder beneath said pistonto the fluid chamber upon movement of the relatively movable memberstoward each other; means in the other piston for establishing a freeflow of fluid from the fluid chamber into the cylinder beneath saidvpiston during the said movement of said members; and a resilientlyactuated unbalanced valve providing communication b etween the cylinderportions-beneath the plstons, said valve bein adapted to establish avariably restricted' ow of fluid from one cylinder into the otherand aconstantly restricted flow in the reverse direction.

8. A shock absorber for cushioning the movement ofv two relativelymovable members comprising, a casing adapted to .be secured to one ofsaid members, presenting a fluid chamber and two cylinders; a piston ineach cylinder; a rock shaft journalled in the casing and operativelyconnected to the other of said movable members; a rocker. arm secured onthe rock shaftvwithin thefcasing, said rocker armhaving a cam portionengaging the one piston for moving it into its cylinder when the `tworelatively movable members are moved toward each other; links connectingthe rocker arm with the other piston;a valve in said'lastmentionedpiston for establishing a free flow of fluid from the fluidchamber to the cylinder portion beneath said piston when the saidmovable members are moved toward each other; means provided by the otherpiston for establishing a radually increasing restriction to the flow 0%the fluid chamber during the said approaching movement of said members,for gradually resisting saidl movement; and a spring loaded, reliefvalve providing communication between the two cylinders for variablyrestricting the flow o f fluid from the one cylinder to the other whenthe one piston is moved into its cylinder, .by the separating movementof the two l relatively movable fluid from beneath said piston tomembers, said relief valve providing a restricted, constant flow bleederpassage from the cylinder in which the fluid 1s compressed by theapproachingbmovement'of the rela- Y l signature. I

` WILLIAM A. .CHRYST ers, to the adjacent cyl-

